B2 visa 10-year multiples entry questions ZhangSan12342014-12-08 15:01:01

Hi again, 

Now that B2 get 10 years multiple entries,  I would like to help grandparents to apply for it, have the visa on hand, then decide when to actually travel to the US. The purpose would be tourism plus visit my family. I have a stupid question,
- if the B2 got approved, is there a timeline that they must travel before that date ? can they travel anytime within the approved 10 years ?
- if they decide to travel 2-3 years later (after the B2 visa is approved), which make the original supporting documents out of date, for examples, travel plan, my legal status in the US, my employment etc, would that put a risk at the port of entry, that they maybe rejected ?

I know most people doesn't have experience with the new 10 year B2 visa policy yet, but still like to hear your opinion. Thanks ahead for sharing 

我觉得没问题。入关的时候解释清楚了为啥申请了签证当时没来就可以了。不过如果英文交流费劲的话，不建议这么干，什么时候真想来再申请多